Group Captive vs TPOA: Which Power Structuring Model Fits Your Factory?
For a factory in Chennai, electricity is not just another monthly expense.
For many manufacturing businesses, power can have a direct impact on production costs, margins and overall competitiveness.
Whether you operate a manufacturing unit in Ambattur, Sriperumbudur, Oragadam or anywhere across Tamil Nadu’s industrial belt, an important question is becoming increasingly relevant:
Can you reduce your electricity cost without compromising reliability?
Rooftop solar is one option.
But for factories with significant electricity consumption, Open Access renewable power can provide another route.
Two structures that frequently come up are:
- Group Captive
- Third-Party Open Access (TPOA)
Both can help eligible industrial consumers procure renewable electricity from a project outside their factory premises. But the ownership structure, capital requirement, risk, regulatory treatment and final economics can be very different.
So, which one is better?
There is no universal answer.
The right choice depends on your factory’s electricity consumption, load profile, capital availability, risk appetite, contract requirements and long-term power strategy.
And there is one number that matters more than the headline solar tariff:
Your landed cost of electricity.
What Is Group Captive Solar?
In a Group Captive structure, multiple electricity consumers participate in the ownership of a power-generating project.
For example, a solar project may be developed outside Chennai with several manufacturing companies participating as captive users.
The participating consumers collectively need to meet the applicable captive ownership and consumption requirements.
Under Rule 3 of the Electricity Rules, 2005, captive users generally need to collectively hold at least 26% of the paid-up share capital of the generating company and consume at least 51% of the electricity generated annually, subject to the applicable rules and structure.
And here’s an important clarification:
26% does not mean 26% of the total project cost.
This is one of the most common misunderstandings around Group Captive projects.
The requirement relates to the paid-up share capital, not the entire project cost.
The electricity generated can then be scheduled and supplied to participating factories through the applicable open-access framework.
In simple terms:
You don’t necessarily need to put a huge solar plant on your factory roof.
Instead, you participate in an off-site renewable-energy project and receive the economic benefit of the renewable electricity supplied to your facility, subject to the applicable regulatory and project structure.
What Is Third-Party Open Access (TPOA)?
TPOA stands for Third-Party Open Access.
Here, the factory purchases renewable electricity from an independent developer or generator through a Power Purchase Agreement (PPA).
The developer generally develops and operates the renewable-energy project.
The factory buys the electricity under the agreed commercial structure and pays the applicable power and open-access charges.
The model is relatively straightforward:
Developer owns the project → Factory buys renewable power → Grid carries the electricity → Factory pays applicable charges.
Unlike Group Captive, the factory does not take an equity stake in the generating project simply to participate as a third-party buyer.
This can make TPOA attractive for businesses that want renewable power but would rather preserve capital for their core business.
Why Are Chennai Factories Looking at Open Access Solar?
The reason is simple.
Industrial electricity consumption can be substantial.
Even a small reduction in the effective cost of every unit can have a meaningful impact on annual operating costs.
For example:
50 lakh units × ₹1/unit saving = ₹50 lakh annual saving
And:
1 crore units × ₹1/unit saving = ₹1 crore annual saving
That is why renewable power procurement is increasingly becoming more than an ESG discussion.
For many businesses, it is a cost-management strategy.
But this is where factories need to be careful.
Don’t Compare Only the Solar Tariff
Suppose a developer tells you:
“Our solar power tariff is ₹X per unit.”
That does not automatically mean your factory’s electricity cost will be ₹X per unit.
Depending on the structure and applicable regulations, your landed cost can involve:
- Solar generation tariff
- Transmission charges
- Wheeling charges
- Banking-related charges
- Cross-subsidy surcharge, where applicable
- Additional surcharge, where applicable
- Scheduling-related costs
- Metering charges
- Applicable taxes and duties
- Other regulatory or contractual costs
So the question should not be:
“Who is offering the lowest solar tariff?”
The better question is:
“Which structure gives my factory the lowest landed electricity cost?”
That is the number your finance team should compare.
Group Captive vs TPOA: The Key Difference
Neither model is automatically better.
The right model is the one that works better for your factory’s numbers.
One Major Advantage of Group Captive
One reason Group Captive receives so much attention is its captive status.
Under the applicable electricity framework, qualifying captive arrangements can receive favourable treatment in relation to certain charges, including cross-subsidy surcharge treatment.
But there is an important condition:
You have to maintain captive status.
The ownership and consumption requirements are not simply formalities.
The 26% paid-up share capital and 51% annual consumption requirements need to be properly maintained in accordance with the applicable rules.
This is why Group Captive should not be viewed simply as:
“Buy a share and get cheaper electricity.”
It requires proper structuring, ongoing compliance and a realistic assessment of your electricity consumption.
The 26% and 51% Rule Explained Simply
Let’s make this simple.
For a qualifying Group Captive structure, captive users generally need to meet:
26% of paid-up share capital
Not 26% of the total project cost.
And:
51% of annual generation consumed
The second number is particularly important.
You cannot simply participate in the ownership structure and ignore your actual electricity consumption.
The economics and compliance of Group Captive are therefore connected to:
Ownership + Consumption
That is why understanding your factory’s electricity profile before committing to a Group Captive structure is so important.
Banking Rules: An Important Difference Between Group Captive and TPOA
This is one of the practical areas that can materially affect renewable-energy economics.
Under Tamil Nadu’s Green Energy Open Access (GEOA) Regulations, 2025, surplus renewable energy can be banked with the distribution licensee, subject to the applicable banking provisions and charges.
The current framework has made banking more structured, and banked energy is subject to applicable banking charges and usage conditions.
These changes affect both Group Captive and TPOA.
However, the way a project is structured and how generation is matched with consumption can affect the economics differently.
Group Captive projects can potentially be structured to better align generation and consumption across participating consumers, while TPOA arrangements depend heavily on the PPA and project structure.
This is why banking should be modelled — not assumed.
The actual impact depends on your factory’s consumption pattern and the applicable regulatory and commercial conditions.
What Happens If Your Factory’s Electricity Consumption Changes?
This is an important question that is often overlooked.
Factories don’t consume the same amount of electricity every year.
Production may increase.
A new production line may be added.
A facility may expand.
A plant may temporarily reduce production.
Or the business may change its operating pattern.
In a Group Captive structure, changes in consumption can become particularly important because captive qualification has consumption-related requirements.
That means your expected electricity consumption should be modelled before committing to the structure.
If your electricity consumption is highly predictable, Group Captive may be easier to structure.
If your consumption is more uncertain, a third-party arrangement may become more attractive commercially.
Why TPOA Can Be Attractive for Factories
The biggest advantage of TPOA is simplicity from the consumer’s perspective.
Your factory does not need to become an equity owner of the renewable-energy project.
Instead:
Developer invests in the project → Factory purchases electricity → Factory pays under the PPA.
This can be particularly attractive for businesses that want to preserve capital for manufacturing, expansion, automation, working capital or other strategic investments.
For example, a Chennai manufacturing company may prefer to deploy ₹10 crore towards:
- New machinery
- Production expansion
- Automation
- Warehouse capacity
- Working capital
rather than committing capital to a renewable-generation asset.
In that situation, TPOA can provide access to renewable electricity without direct ownership of the generating project.
But TPOA Is Not Automatically Cheaper
This is where businesses need to look beyond the headline tariff.
A third-party arrangement can involve charges that may not apply, or may apply differently, under a qualifying captive structure.
The treatment of:
- Cross-subsidy surcharge
- Additional surcharge
- Transmission and wheeling charges
- Banking
- Other applicable open-access charges
needs to be evaluated for the specific transaction.
The final economics depend on the Tamil Nadu regulatory environment, consumer category, project location, contract structure and applicable charges at the time of implementation.
So again:
Don’t ask, “Which model has the cheaper solar tariff?”
Ask:
“Which model gives my factory the lower landed electricity cost?”
Group Captive vs TPOA: Capital Investment
Group Captive
Your business participates in the ownership structure.
This generally means some level of capital commitment or equity participation.
However, remember:
The 26% requirement relates to paid-up share capital — not 26% of the total project cost.
The advantage is that the consumer participates in the project economics and captive structure.
The downside is that capital is tied to the project.
TPOA
The developer owns and operates the generation project.
Your factory primarily commits through the PPA rather than taking ownership in the generating asset.
This can reduce the upfront capital requirement.
For businesses that want to preserve cash for production and expansion, that can be a major advantage.
Where Does the Risk Sit?
Every energy structure has risk.
The question is:
Where does that risk sit?
In Group Captive, the consumer has an ownership relationship with the project and therefore needs to understand:
- Project performance
- Captive compliance
- Ownership structure
- Consumption requirements
- Long-term project economics
In TPOA, the developer generally carries more of the asset-development and operational responsibility.
However, the factory becomes more dependent on the developer’s contractual and operational performance.
Before signing a long-term PPA, review:
- Developer track record
- Project quality
- PPA terms
- Tariff escalation
- Contract duration
- Exit provisions
- Minimum purchase obligations
- Change-in-law clauses
- Force majeure provisions
- Curtailment provisions
- Payment security
- Project performance guarantees
A low tariff is not enough.
A good contract matters just as much.
Which Model Offers Better Long-Term Price Visibility?
Both models can provide better visibility than relying entirely on conventional grid power.
But the mechanism is different.
With a well-structured Group Captive project, the consumer participates in the ownership structure and can potentially benefit from the economics of a long-term renewable asset.
With TPOA, price certainty depends heavily on the PPA terms.
Your agreement could include:
- Fixed tariff
- Tariff escalation
- Hybrid pricing
The contract structure should be evaluated against your factory’s expected electricity demand over the applicable period.
Don’t sign a long-term PPA simply because today’s tariff looks attractive.
Model the entire commercial relationship.
Which Is Better for an MSME Factory?
For smaller industrial consumers, the answer may often lean towards simplicity.
If your electricity consumption is moderate and your factory does not want to commit capital to a generation project, a third-party structure may be easier to understand commercially.
However, eligibility for open access and the actual economics must be assessed against the applicable rules.
The broader Green Energy Open Access framework includes provisions around eligible consumers with contracted demand or sanctioned load of 100 kW or more, with special treatment for captive consumers in certain circumstances.
But:
Eligibility is only the starting point.
It does not automatically mean that open access will be economically attractive for every 100 kW consumer.
Your actual savings depend on consumption, tariff, open-access charges, project location and other applicable factors.
Which Is Better for a Large Chennai Factory?
For a large industrial consumer with predictable electricity demand, Group Captive can become particularly interesting.
For example, a factory that:
- Consumes electricity throughout the year
- Has stable production
- Has significant annual electricity consumption
- Can commit to a long-term energy strategy
- Is comfortable with equity participation
- Wants to optimise landed power cost
- Has a capable finance and compliance team
may be able to justify the additional complexity of a Group Captive structure.
But the numbers still need to be modelled.
A large factory should never choose Group Captive simply because someone says:
“CSS is not applicable.”
The complete financial model matters — including the applicable banking treatment.
What If Your Factory Doesn’t Want to Invest Capital?
This is where TPOA can become more attractive.
Imagine a factory that wants renewable electricity but does not want to invest directly in a solar project.
It may prefer:
No project ownership → Lower direct capital commitment → Long-term PPA → Pay for contracted electricity
This can allow management to focus its capital on manufacturing rather than power generation.
For companies with limited capital budgets, this can be a strong reason to evaluate third-party procurement.
A Chennai Factory Example
Let’s consider a hypothetical manufacturing unit near Sriperumbudur consuming 1 crore units of electricity per year.
The management is considering renewable power.
Option A — Group Captive
The company participates in a qualifying Group Captive project.
It contributes to the ownership structure based on the applicable paid-up share capital requirements.
The project supplies renewable electricity through open access.
The company needs to maintain the applicable captive conditions and manage its long-term participation.
Option B — TPOA
The company signs a long-term PPA with a renewable-energy developer.
The developer owns the project.
The factory pays for electricity according to the agreed commercial terms and applicable open-access charges.
So which one wins?
You cannot answer that from the tariff alone.
You need to calculate:
Grid landed cost − Renewable landed cost = Effective saving per unit
Then:
Effective saving per unit × Annual renewable consumption = Annual savings
And finally:
Investment ÷ Annual savings = Simple payback
The calculation should use the factory’s actual electricity bills and expected consumption profile.
Don’t Forget Your Factory’s Load Profile
This may be one of the most important parts of the entire analysis.
Two factories can consume the same number of units and still have completely different electricity economics.
For example:
Factory A may consume most of its electricity during the daytime.
Factory B may operate three shifts.
Factory C may have significant evening and night loads.
Factory D may have highly seasonal production.
Those differences can materially affect the economics of renewable power procurement, particularly when banking and settlement rules are considered.
A proper feasibility study should therefore examine:
- Monthly electricity consumption
- Day/night consumption
- Peak demand
- Contract demand
- Time-of-day usage
- Production schedule
- Seasonal variation
- Existing rooftop solar
- Future expansion
- Expected renewable-power requirement
The goal is not to maximise solar procurement.
The goal is to optimise your electricity portfolio.
Group Captive + Rooftop Solar: Can You Use Both?
Yes.
A factory does not necessarily have to choose only one renewable-energy strategy.
A manufacturing facility could potentially use:
Rooftop Solar + Group Captive + Grid Power
or:
Rooftop Solar + TPOA + Grid Power
For example, rooftop solar can generate electricity directly at the factory during suitable daytime hours.
Open Access can then cover a portion of the remaining electricity requirement.
Grid power can act as the balancing source.
This blended approach can sometimes be more practical than trying to meet the entire electricity requirement through a single source.
The right combination depends on the factory’s load profile and applicable regulatory and commercial rules.
What Should Your Finance Team Ask Before Choosing?
Before signing any agreement, ask for a detailed financial model.
At minimum, it should show:
1. Existing electricity cost
What is your actual average landed cost from the grid?
2. Proposed renewable tariff
What will the renewable generation cost?
3. Open-access charges
What transmission, wheeling, banking and other applicable charges will be added?
4. Surcharges
Which surcharges apply to the specific structure?
5. Taxes and duties
What additional government charges need to be considered?
6. Annual generation
How much electricity is the project expected to generate?
7. Your allocation
How much of the generation will actually be allocated to your factory?
8. Banking and settlement
How will excess or shortfall energy be handled?
9. Contract period
How long are you committed?
10. Exit conditions
What happens if your factory closes, relocates, reduces production or changes its energy requirements?
These questions can prevent expensive surprises later.
7 Mistakes Factories Should Avoid
Mistake 1: Choosing Based Only on Solar Tariff
A ₹4/unit solar tariff does not necessarily mean ₹4/unit delivered electricity. Calculate the complete landed cost.
Mistake 2: Ignoring Consumption Changes
If your factory plans to expand or reduce production, model those changes before committing.
Mistake 3: Assuming Group Captive Is Risk-Free
Captive status depends on compliance with applicable requirements, including ownership and consumption thresholds.
Mistake 4: Signing a PPA Without Reading Exit Clauses
A long-term contract is a major commercial commitment. Understand what happens if circumstances change.
Mistake 5: Ignoring Developer Creditworthiness
Your renewable-energy strategy should not depend on a developer that may struggle financially or operationally.
Mistake 6: Comparing Only Two Options
Don’t compare just Group Captive and TPOA. Model at least:
- Grid-only
- Rooftop Solar
- Group Captive
- TPOA
Then compare them using consistent assumptions.
Mistake 7: Ignoring Your Load Profile
The same renewable tariff can produce very different savings for two factories with different consumption patterns. Your electricity data should drive the decision.
Group Captive vs TPOA: Quick Decision Guide
Consider Group Captive if:
- Your factory has high and predictable electricity consumption.
- You are comfortable with equity participation.
- You are looking for a long-term renewable-energy strategy.
- Your finance team can manage ownership and compliance requirements.
- The captive structure produces a better landed-cost outcome after all applicable charges.
Consider TPOA if:
- You want minimal upfront capital investment.
- You don’t want to own the solar asset.
- You prefer a simpler power-procurement relationship.
- You want the developer to handle project ownership and operations.
- The PPA provides an attractive landed electricity cost after applicable charges.
Consider Rooftop Solar if:
- You have sufficient roof space.
- You have strong daytime electricity consumption.
- You want generation directly at the factory.
- You want to reduce grid consumption through on-site generation.
For many factories, the answer may actually be a combination of these strategies.
The Right Question Isn’t “Group Captive or TPOA?”
For a Chennai factory, the better question is:
“What power structure gives my business the lowest risk-adjusted landed electricity cost over the applicable contract period?”
That’s a much more useful way to think about renewable energy.
Group Captive can provide strong economics when the ownership and consumption requirements are properly structured.
TPOA can provide a simpler route to renewable electricity without direct project ownership.
Rooftop solar can provide on-site generation where suitable roof space exists.
And conventional grid power will continue to play an important role in balancing the factory’s requirements.
The best strategy isn’t necessarily one technology or one contract.
It is the right energy portfolio for your business.
Frequently Asked Questions
What is Group Captive solar power?
Group Captive is a structure where multiple electricity consumers collectively participate in the ownership of a renewable-energy generating project and receive electricity through the applicable open-access framework, subject to the relevant ownership and consumption requirements.
What is Third-Party Open Access (TPOA)?
TPOA is a structure where a factory purchases renewable electricity from an independent developer or generator under a Power Purchase Agreement, without taking an ownership stake in the generating project.
What is the equity requirement for Group Captive in India?
Captive users generally need to collectively hold at least 26% of the paid-up share capital of the generating company and consume at least 51% of the annual electricity generated, subject to the applicable rules and structure. The 26% figure refers to paid-up share capital, not 26% of total project cost.
Is TPOA cheaper than Group Captive?
Not automatically. TPOA can require less upfront capital because the consumer does not own the generating asset. However, the final economics depend on the renewable tariff, open-access charges, applicable surcharges, banking treatment, PPA terms and the factory’s consumption profile. The right answer comes from the landed-cost calculation, not the headline tariff.
Which is better for a large factory — Group Captive or TPOA?
A large factory with predictable electricity consumption and the appetite for equity participation may find Group Captive attractive. A factory that wants to preserve capital and avoid direct project ownership may prefer TPOA. Both options should be modelled against actual electricity consumption before making a decision.
Can a factory use rooftop solar together with Group Captive or TPOA?
Yes. Depending on the applicable regulatory and commercial framework, a factory may potentially combine rooftop solar with Group Captive or TPOA, while using grid electricity to balance its remaining requirement. The right combination depends on the factory’s load profile and applicable rules.
How does energy banking affect the economics?
Banking allows surplus renewable energy to be handled under the applicable open-access framework, but current Tamil Nadu regulations include banking-related charges and conditions. The impact depends on the structure, generation profile and consumption pattern, so banking should be included in the financial model rather than treated as an assumption.
How KinetiQ Energy Can Help Your Factory Evaluate Renewable Power
Choosing between Group Captive, TPOA, rooftop solar or a combination of these should begin with your electricity data — not a sales pitch.
At KinetiQ Energy, the objective is to understand your factory’s actual power consumption and evaluate the renewable-energy structure that makes commercial sense for your business.
A proper assessment can consider:
- Historical electricity bills
- Monthly consumption
- Contract demand
- Load profile
- Rooftop potential
- Renewable-power requirement
- Open-access feasibility
- Group Captive suitability
- TPOA options
- Applicable charges and banking treatment
- Expected savings
- Long-term financial impact
The objective is simple:
Understand your current power cost.
Model the alternatives.
Compare the landed cost.
Choose the structure that makes financial sense for your factory.
For Chennai’s manufacturing sector, renewable electricity is becoming more than an ESG initiative.
It is becoming a cost-management strategy.
Neither Group Captive nor TPOA is universally better.
The right choice depends on your:
Electricity consumption + load profile + capital availability + contract requirements + regulatory exposure + long-term business plans.
For a Chennai factory considering renewable power in 2026, the smartest first step is not signing a PPA.
It is getting the numbers right.
Your factory’s electricity bill contains the starting point.
The right renewable-energy strategy should be built around that data.